PI3K-dependent activity is frequently elevated due to mutation of PIK3CA, a gene encoding the p110α catalytic subunit of PI3K (PI3K p110α), and the absence of the phosphatase and tensin homolog(PTEN) protein, a tumor suppressor with an important role in regulating the PI3K antiapoptotic and survival pathway [7], [8]. The gene discussed is PIK3CA; the disease is neoplasm.